A precise blood transfusion evaluation model for aortic surgery: a single-center retrospective study.

Cardiac aortic surgery is an extremely complicated procedure that often requires large volume blood transfusions during the operation. Currently, it is not possible to accurately estimate the intraoperative blood transfusion volume before surgery. Therefore, in this study, to determine the clinically precise usage of blood for intraoperative blood transfusions during aortic surgery, we established a predictive model based on machine learning algorithms. We performed a retrospective analysis on 4,285 patients who received aortic surgery in Beijing Anzhen Hospital between January 2018 and September 2022. Ultimately, 3,654 patients were included in the study, including 2,557 in the training set and 1,097 in the testing set. By utilizing 13 current mainstream models and a large-scale cardiac aortic surgery dataset, we built a novel machine learning model for accurately predicting intraoperative red blood cell transfusion volume. Based on the transfusion-related risk factors that the model identified, we also established the relevant variables that affected the results. The results revealed that decision tree models were the most suitable for predicting the blood transfusion volume during aortic surgery. In particular, the mean absolute error for the best-performing extremely randomized forest model was 1.17 U, while the R2 value was 0.50. Further exploration into intraoperative blood transfusion during aortic surgery identified erythrocytes, estimated operation duration, body weight, sex, red blood cell count, and D-dimer as the six most significant risk factors. These factors were subsequently analyzed for their influence on intraoperative blood transfusion volume in relevant patients, as well as the protective threshold for prediction. The novel intraoperative blood transfusion prediction model for cardiac aorta surgery in this study effectively assists clinicians in accurately calculating blood transfusion volumes and achieving effective utilization of blood resources. Furthermore, we utilize interpretability technology to reveal the influence of critical risk factors on intraoperative blood transfusion volume, which provides an important reference for physicians to provide timely and effective interventions. It also enables personalized and precise intraoperative blood usage.

Predictors of and predictive nomogram for cut-out of proximal femur nail anti-rotation device in intertrochanteric fractures.

PURPOSE: This study determined independent predictors and developed a predictive nomogram for failed correction of intertrochanteric fractures due to cut-out of the proximal femur nail anti-rotation (PFNA) device. METHODS: Demographic and radiological data of 592 adult patients with intertrochanteric fractures (AO 31A) treated by PFNA were collected retrospectively. Independent predictors of cut-out were obtained through univariate and multivariate analyses, and a predictive nomogram was established. The discrimination, calibration, and clinical utility of the nomogram were based on receiver operating characteristic curve (AUC), concordance index (C-index), calibration curve, and decision curve analysis, respectively. RESULTS: Overall, 18 (3.04%) cases of cut-out occurred. Independent predictors according to the multivariate analysis were body mass index (BMI), poor-to-acceptable quality of reduction, PFNA blade position, and tip-apex distance (TAD). AUC of the nomogram was 0.849, and C-index was 0.849 (95% CI [0.844-0.854]). Bootstrapping yielded a corrected C-index of 0.849. The calibration and decision curves indicated good agreement and clinical benefit of the nomogram. CONCLUSION: A reliable predictive nomogram was developed for cut-out of the PFNA in intertrochanteric fractures, based on BMI, quality of reduction, blade position, and TAD.

A Rheological Model for Evaluating the Behavior of Shear Thickening of Highly Flowable Mortar.

Neither the modified Bingham model nor the Herschel-Bulkley model can be used to characterize and calculate the performance of shear thickening of highly flowable mortar because of their incalculability of the rheological parameters. A new exponential rheological model was established to solve the characterization and calculation of shear thickening of the lubrication layer (highly flowable mortar) during the pumping of concrete in this paper. This new exponential rheological model has three rheological parameters, namely, yield stress, consistency coefficient, and consistency exponent. They can quantitatively describe the yield stress, differential viscosity, and shear thickening degree of highly flowable mortar. The calculating results of the rheological parameters of the newly established model for the mortars with different compositions showed that the consistency exponent of mortar decreased with the increase of its sand-binder ratio or the dosage of fly ash in the binder. This indicates that the shear thickening degree of mortar decreases. The consistency exponent of mortar initially decreases and subsequently increases with the increase in silica fume content or the dosage of the superplasticizer. It illustrates that the degree of the shear thickening of mortar initially decreased and subsequently increased. These varying patterns were confirmed by the rheological experiment of mortars.

Analysis of a safe utilization algorithm for retired power batteries from new energy vehicles.

The graded utilization of waste batteries has gained research significance due to recent reports of new energy vehicle lithium-ion batteries exploding whilst awaiting recycling or in end-of-life storage. In this study, we innovatively selected battery performance parameters such as the internal resistance, charge and discharge rate, and current maximum available capacity to evaluate the safety of retired power batteries from the perspective of inducing thermal runaway. A fractional calculus theory was then introduced, and the fractional second-order resistance as well as a capacitance model and an adaptive genetic algorithm were established for the identification of the parameters. An improved dual-scale filtering algorithm was generated, which combined the extended Kalman filter algorithm and the unscented Kalman filter algorithm to improve the accuracy of the parameter estimation. The final test outcomes indicated that the equivalent circuit model optimized by incorporating multiple filtering algorithms had error rates of 1.87 %, 1.65 %, and 1.27 % for the state of charge of the battery in three different operating condition testbeds, with average errors of 0.62 %, 0.69 %, and 0.59 %, respectively. When an initial experimental platform was constructed for the detection of the parameters, the voltage error quickly stabilized to within 0.03 V. It also displayed many advantages of data detection and calculation, such as faster convergence, faster tracking, and the highest result accuracy when compared with the battery model using other algorithms. This experiment highlighted that a fractional second-order resistive-capacitive circuit equivalent battery state detection model incorporating various filtering algorithms has practicality and feasibility.

Thermal and Magnetic Dual-Responsive Catheter-Assisted Shape Memory Microrobots for Multistage Vascular Embolization.

Catheters navigating through complex vessels, such as sharp turns or multiple U-turns, remain challenging for vascular embolization. Here, we propose a novel multistage vascular embolization strategy for hard-to-reach vessels that releases untethered swimming shape-memory magnetic microrobots (SMMs) from the prior catheter to the vessel bifurcation. SMMs, made of organo-gel with magnetic particles, ensure biocompatibility, radiopacity, thrombosis, and fast thermal and magnetic responses. An SMM is initially a linear shape with a 0.5-mm diameter at 20 °C inserted in a catheter. It transforms into a predetermined helix within 2 s at 38 °C blood temperature after being pushed out of the catheter into the blood. SMMs enable agile swimming in confined and tortuous vessels and can swim upstream using helical propulsion with rotating magnetic fields. Moreover, we validated this multistage vascular embolization in living rabbits, completing 100-cm travel and renal artery embolization in 2 min. After 4 weeks, the SMMs maintained the embolic position, and the kidney volume decreased by 36%.

tPA-anchored nanorobots for in vivo arterial recanalization at submillimeter-scale segments.

Micro/nanorobots provide a promising approach for intravascular therapy with high precision. However, blood vessel is a highly complex system, and performing interventional therapy in those submillimeter segments remains challenging. While micro/nanorobots can enter submillimeter segments, they may still comprise nonbiodegradable parts, posing a considerable challenge for post-use removal. Here, we developed a retrievable magnetic colloidal microswarm, composed of tPA-anchored Fe3O4@mSiO2 nanorobots (tPA-nbots), to archive tPA-mediated thrombolysis under balloon catheter-assisted magnetic actuation with x-ray fluoroscopy imaging system (CMAFIS). By deploying tPA-nbot transcatheter to the vicinity of the thrombus, the tPA-nbot microswarms were magnetically actuated to the blood clot at the submillimeter vessels with high precision. After thrombolysis, the tPA-nbots can be retrieved via the CMAFIS, as demonstrated in ex vivo organ of human placenta and in vivo carotid artery of rabbit. The proposed colloidal microswarm provides a promising robotic tool with high spatial precision for enhanced thrombolysis with low side effects.

Preshaped 4D Photocurable Ultratough Organogel Microcoils for Personalized Endovascular Embolization.

Endovascular embolization using microcoils can be an effective technique to treat artery aneurysms. However, microcoils with fixed designs are difficult to adapt to all aneurysm types. In this paper, a photocurable ultratough shape memory organogel with a curing time of only 2 s and megapascal-level mechanical properties is proposed. Then, it is used to manufacture the personalized 4D microcoil with a wire diameter of only 0.3 mm. The improved mechanical modulus (511.63 MPa) can reduce the possibility of microcoils' fracture during embolization. Besides, the fast body-temperature-triggering shape memory ability makes the 4D microcoil applicable in vivo. These 4D microcoils are finally delivered into the rabbit, and successfully blocked the blood flow inside different aneurysms, with neoendothelial cells and collagen fibers growing on the microcoil surface snugly, indicating full aneurysm recovery. This 4D organogel microcoil can potentially be used in personalized clinical translation on human beings.

System identification algorithm analysis of acupuncture effect on mean blood flux of contralateral hegu acupoint.

Background. Acupoints (belonging to 12 meridians) which have the same names are symmetrically distributed on the body. It has been proved that acupoints have certain biological specificities different from the normal parts of the body. However, there is little evidence that acupoints which have the same name and are located bilaterally and symmetrically have lateralized specificity. Thus, researching the lateralized specificity and the relationship between left-side and right-side acupuncture is of special importance. Methodology and Principal Findings. The mean blood flux (MBF) in both Hegu acupoints was measured by Moor full-field laser perfusion imager. With the method of system identification algorithm, the output distribution in different groups was acquired, based on different acupoint stimulation and standard signal input. It is demonstrated that after stimulation of the right Hegu acupoint by needle, the output value of MBF in contralateral Hegu acupoint was strongly amplified, while after acupuncturing the left Hegu acupoint, the output value of MBF in either side Hegu acupoint was amplified moderately. Conclusions and Significance. This paper indicates that the Hegu acupoint has lateralized specificity. After stimulating the ipsilateral Hegu acupoint, symmetry breaking will be produced in contrast to contralateral Hegu acupoint stimulation.

Localization diagnosis of adrenocorticotrophic hormone-dependent Cushing's syndrome: two case reports and literature review.

BACKGROUND: The common causes of adrenocorticotrophic hormone (ACTH)-dependent Cushing's syndrome (CS) include Cushing's disease (CD) and ectopic ACTH syndrome (EAS). The differential diagnosis and lesion location of CD and EAS often bring great difficulties to clinical diagnosis and treatment. This article reports the localization diagnosis, treatment, and follow-up results of two patients with ACTH-dependent CS with different causes and reviews the literature. CASE DESCRIPTION: Case 1: a 29-year-old female patient attended the clinic because of irregular menstruation, weight gain, and violaceous striae. The low dose dexamethasone suppression test (LDDST) was not suppressed, and the high dose dexamethasone suppression test (HDDST) suggested the results of serum cortisol and 24-h urine free cortisol were contradictory. Magnetic resonance imaging (MRI) indicated pituitary microadenoma, and bilateral inferior petrosal sinus sampling (BIPSS) indicated ACTH was centrally secreted. CD was diagnosed. The patient underwent transsphenoidal surgery, and the symptoms of CS were improved after the operation. A natural pregnancy occurred more than half a year after the surgery, and a healthy baby boy was delivered 9 months later. Case 2: a 29-year-old female patient complained of facial redness and elevated blood pressure. Examination showed refractory hypokalemia and abnormally elevated serum cortisol and ACTH. Androgens also increased. Neither LDDST nor HDDST was inhibited. Chest-to-pelvis computed tomography (CT) scan revealed a soft tissue mass in the anterior mediastinum, considered as a possible thymoma. EAS and thymoma were diagnosed. An anterior mediastinal mass resection was performed, and pathological results suggested thymic carcinoid weakly positive for ACTH. After the operation, hypertension and hypokalemia were relieved, and cortisol, ACTH and androgens returned to normal levels. CONCLUSIONS: The differentiation between CD and EAS should be comprehensively evaluated in combination with the medical history, function tests, pituitary MRI, and other tests. If the function test results are discordant or pituitary MRI shows the lesion diameter is less than 6 mm, BIPSS should be further performed to confirm the diagnosis. The lesions of EAS are complex and diverse, and it is necessary to pay attention to imaging examinations of the neck-to-pelvis to locate lesion and provide direction for subsequent treatment.

Response and safety of whole-brain radiotherapy plus temozolomide for patients with brain metastases of non-small-cell lung cancer: A meta-analysis.

OBJECTIVE: The aim of the present work was to investigate the response and safety of whole-brain radiotherapy (WBRT) plus temozolomide (TMZ) for patients with brain metastases of non-small-cell lung cancer (NSCLC). METHODS: The electronic databases of Pubmed, EMbase, Cochrane, Wangfang, china national knowledge infrastructure (CNKI), and Google scholar were systematically searched to identify the prospective randomized trials relevant to WBRT plus TMZ for patients with brain metastases of NSCLC. The data associated with treatment response and toxicity were extracted from original included studies. The relative risk (RR) for treatment response and toxicity between WBRT+TMZ and WBRT alone was pooled by fixed or random effect model. Publication bias was investigated by Begg's funnel plot and Egger's line regression test. RESULTS: Twenty-five clinical trials fulfilled the inclusion criteria and were included in the meta-analysis. The pooled results showed WBRT+TMZ can significant improve the objective response rate (ORR) compared with WBRT alone (RR = 1.43, 95% confidence interval [CI] 1.32-1.55, p < 0.05) under a fixed effect model. WBRT+TMZ significantly increased the III-IV hematological toxicity compared to WBRT alone (RR = 1.66, 95% CI 1.12-2.54, p < 0.05) in the fixed effect model. Grade III-IV gastrointestinal toxicity was increased in WBRT+TMZ compared to WBRT alone (RR = 1.72, 95% CI 1.29-2.30, p < 0.05). Begg's funnel plot and Egger's line regression test indicated publication bias. CONCLUSION: Based on the present work, WBRT+TMZ can improve the ORR for brain metastases of NSCLC, but the risk of treatment-associated grade III/IV hematological toxicity and gastrointestinal toxicity were also increased compared to WBRT alone.

METTL3 participates in glioma development by regulating the methylation level of COL4A1.

PURPOSE: The role of RNA methylation in human cancers has emerged. Its biological function in glioma development is explored in the present study. METHODS: Differential levels and prognostic potentials of COL4A1 and METTL3 in glioma were analyzed by bioinformatic method. The regulatory effect of METTL3 on COL4A1 was assessed through qRT-PCR, MeRIP and dual-luciferase reporter assay. Their biological functions in influencing proliferative and metastatic capacities of glioma cells were examined by EdU, colony formation and Transwell assay, respectively. RESULTS: COL4A1 was upregulated in glioma tissues, and METTL3 was downregulated. Knockdown of METTL3 in U87 and U251 cells could reduce the methylation level of COL4A1 and upregulate its expression level. Intervention of COL4A1 suppressed proliferative and metastatic capacities of glioma cells, while intervention of METTL3 yielded the opposite results. CONCLUSION: METTL3 reduces the methylation level of COL4A1 and upregulates its expression level, which further stimulates the malignant development of glioma. METTL3/COL4A1 can be potential therapeutic targets of glioma.

Efficacy and safety of MIL60 compared with bevacizumab in advanced or recurrent non-squamous non-small cell lung cancer: a phase 3 randomized, double-blind study.

BACKGROUND: We compared the efficacy, safety, and immunogenicity of MIL60 with reference bevacizumab as first-line treatment in patients with advanced or recurrent non-squamous non-small cell lung cancer (NSCLC) in this phase 3, randomized, double-blind study. METHODS: Patients with untreated advanced or recurrent NSCLC were randomized (1:1 ratio) to receive either MIL60 or bevacizumab in combination with paclitaxel/carboplatin. Patients with non-progressive disease continued maintenance single-agent MIL60 until disease progression, or intolerable toxicity. The primary endpoint was the 12-week objective response rates (ORR12) by independent review committee (IRC) using RECIST 1.1. Bioequivalence was established if the ORR ratio located between 0.75 and 1/0.75. The trial was registered with clinicaltrials.gov (NCT03196986). FINDINGS: Between Aug 23, 2017, and May 8, 2019, 517 patients were randomly assigned to MIL60 group (n=257) and bevacizumab group (n=260). In the full analysis set (FAS) population including all randomized and evaluable patients who received at least one dose of MIL60 or bevacizumab, the ORR12 in MIL60 group and bevacizumab group were 48.6% and 43.1%, respectively. The ORR ratio of these two groups were 1.14 (90% CI 0.97-1.33), which fell within the pre-specified equivalence boundaries (0.75-1/0.75). The median DOR was 5.7 months (95% CI 4.5-6.2) for MIL60 and 5.6 months (95% CI 4.3-6.4) for bevacizumab. No significant difference was noted in median PFS (7.2 vs. 8.1 months; HR 1.01, 95% CI 0.78-1.30, p=0.9606) and OS (19.3 vs. 16.3 months; HR 0.81, 95% CI 0.64-1.02, p=0.0755). Safety and tolerability profiles were similar between the two groups. No patient detected positive for Anti-drug antibody (ADA). INTERPRETATION: The efficacy, safety and immunogenicity of MIL60 were similar with bevacizumab, providing an alternative treatment option for advanced or recurrent non-squamous NSCLC. FUNDING: This study was sponsored by Betta Pharmaceutical Co., Ltd.

Preparative separation of phenolic compounds from Halimodendron halodendron by high-speed counter-current chromatography.

Three phenolic compounds, p-hydroxybenzoic acid (1), isorhamnetin-3-O-ß-D-rutinoside (2), and 3,3'-di-O-methylquercetin (5), along with a phenolic mixture were successfully separated from the ethyl acetate crude extract of Halimodendron halodendron by high-speed counter-current chromatography (HSCCC) with chloroform-methanol-water-acetic acid (4:3:2:0.05, v/v) as the two-phase solvent system. The phenolic mixture from HSCCC was further separated by preparative HPLC and purified by Sephadex LH-20 to afford quercetin (3) and 3-O-methylquercetin (4). Seven hundred mg of ethyl acetate crude extract was separated by HSCCC to obtain six fractions which were then analyzed by high performance liquid chromatography (HPLC). The HSCCC separation obtained total of 80 mg of the mixture of quercetin (3) and 3-O-methylquercetin (4) (26.43% and 71.89%, respectively) in fraction 2, 14 mg of 3,3'-di-O-methylquercetin (5) at 95.14% of purity in fraction 3, 15 mg of p-hydroxybenzoic acid (1) at 92.83% of purity in fraction 5, 12 mg of isorhamnetin-3-O-ß-D-rutinoside (2) at 97.99% of purity in fraction 6. This is the first time these phenolic compounds have been obtained from H. halodendron, and their chemical structures identified by means of physicochemical and spectrometric analysis.

Chemical analysis and biological activity of the essential oils of two valerianaceous species from China: Nardostachys chinensis and Valeriana officinalis.

In order to investigate essential oils with biological activity from local wild plants, two valerianaceous species, Nardostachys chinensis and Valeriana officinalis, were screened for their antimicrobial and antioxidant activity. The essential oils were obtained from the roots and rhizomes of the two plants by hydro-distillation, and were analyzed for their chemical composition by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Calarene (25.31%), aristolone (13.35%), α-selinene (7.32%) and ß-maaliene (6.70%) were the major compounds of the 23 identified components which accounted for 92.76% of the total oil of N. chinensis. Patchoulol (16.75%), α-pinene (14.81%), and ß-humulene (8.19%) were the major compounds among the 20 identified components, which accounted for 88.11% of the total oil of V. officinalis. Both oils were rich in sesquiterpene hydrocarbons as well as their oxygenated derivatives. Essential oils were shown to have broad spectrum antibacterial activity with MIC values that ranged from 62.5 µg/mL to 400 µg/mL, and IC(50) values from 36.93 µg/mL to 374.72 µg/mL. The oils were also shown to have moderate antifungal activity to Candida albicans growth as well as inhibition of spore germination of Magnaporthe oryzae. Two essential oils were assessed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, ß-carotene bleaching and ferrozine-ferrous ions assays, respectively, to show moderate antioxidant activity. Results suggest that the isolated essential oils could be used for future development of antimicrobial and antioxidant agents.

Flavonoids from Halostachys caspica and their antimicrobial and antioxidant activities.

Seven flavonoids have been isolated from the aerial parts of Halostachys caspica C. A. Mey. (Chenopodiaceae) for the first time. By means of physicochemical and spectrometric analysis, they were identified as luteolin (1), chrysin (2), chrysin 7-O-ß-D-glucopyranoside (3), quercetin (4), quercetin 3-O-ß-D-glucopyranoside (5), isorhamentin-3-O-ß-D-glucopyranoside (6), and isorhamentin-3-O-ß-D-rutinoside (7). All flavonoids were evaluated to show a broad antimicrobial spectrum of activity on microorganisms including seven bacterial and one fungal species as well as pronounced antioxidant activity. Among them, the aglycones with relatively low polarity had stronger bioactivity than their glycosides. The results suggested that the isolated flavonoids could be used for future development of antimicrobial and antioxidant agents, and also provided additional data for supporting the use of H. caspica as forage.

[Applications of near infrared reflectance spectroscopy technique to determination of forage mycotoxins].

The near infrared reflectance spectroscopy technique (NIRS) has been explored at many fields such as agriculture, food, chemical, medicine, and so on, due to its rapid, effective, non-destructive, and on-line characteristics. Fungi invasion in forage materials during processing and storage would generate mycotoxins, which were harmful for people and animal through food chains. The determination of mycotoxins included the overelaborated pretreatments such as milling, extracting, chromatography and subsequent process such as enzyme linked immunosorbent assay, high performance liquid chromatography, and thin layer chromatography. The authors hope that high precision and low detection limit spectrum instrument, and software technology and calibration model of mycotoxins determination, will fast measure accurately the quality and quantity of mycotoxins, which will provide basis for reasonable process and utilization of forage and promote the application of NIRS in the safety livestock product.

Male mammary gland development after apatinib therapy in advanced gastric cancer: A case report.

RATIONALE: Most gastric cancer patients are diagnosed at mid- to late-stage and lose the chance of radical surgery, medical treatment is especially important to prolong the survival of patients. Apatinib mesylate, which is a small molecule vascular endothelial growth factor receptor 2 tyrosine kinase inhibitor, could be used as antiangiogenesis therapy for gastric cancer. PATIENT CONCERNS: A 67-year-old man sought medical care for upper abdominal discomfort. DIAGNOSIS: The patient was diagnosed as mixed medullary differentiated gastric adenocarcinoma, and immunohistochemistry suggested HER-2 (2+). INTERVENTIONS: The patient received chemotherapy consisting of oxaliplatin combined with S-1 as first-line treatment, and targeted therapy with apatinib mesylate as second-line treatment. OUTCOMES: After 4 months of first-line chemotherapy, the patient received apatinib treatment immediately at a dose of 500 mg/d orally and died of cardiac arrest with 8.5 months of overall survival. During this period of targeted therapy with apatinib mesylate, this male patient suffered mammary gland development besides other common adverse reactions. LESSONS: This case report is the first to report the case of male mammary gland development after oral apatinib.

[Study on hyper-spectral remote sensing models for monitoring damage of Oedaleus asiaticus (Orthoptera : Acrididae)].

In the present paper, the ASD Field Spec Pro FRTM spectroradiometer was used for measuring damages of O. asiaticus in Xilin GolLeague, Inner Mongolia. First, the hyper-spectral data were analyzed and the canopy reflectance spectral data were compared between the healthy leaves and the infected leaves of Leymus chinensis. Second, the regression models between the leaf area index (LAI) and the hyper-spectral parameters were built, and different varieties of the O. asiaticus damage were used to test its precision. The results showed that there was a high correlation of three hyper-spectral data between the LAI and the first derivative data. Moreover the disease index (DI) model, which is mostly suitable for use in indicating the intensity of grasshoppers damage in the study area, containing the ratio of the sum of first derivative within red peak regions (620-760 nm, SDr) to the sum of first derivative within blue peak regions (430-470 nm, SDb) was the best one. From the model, there were no damage if DI was over 72.43, slight damage if DI was between 51.57 and 79.83, and serious damage if DI was less than 51.57. The model had the highest prediction precision with the correlation coefficient of prediction of 0.948, and the mean relative error of 3.928%. These results showed a good prediction of the model and indicated that the grasshopper damage could be estimated at the canopy level using hyper-spectral reflectance.

[Application of near-infrared reflectance spectroscopy to the discrimination of salt tolerance of alfalfa cultivars].

Near infrared reflectance spectroscopy is a new developed method able to analyse the content of specific compound in the detected sample quickly and efficiently, and has been wildly used in many fields such as evaluation of nutrition value of forage, cultivar discrimination and so on. In the present paper a new method was developed for the discrimination of salt tolerance of alfalfa cultivars by Fourier transform near infrared reflectance spectroscopy. Firstly absorbance spectrum generated by Fourier transform near infrared spectrometry was used to classify twenty alfalfa cultivars. These cultivars were obviously clustered into two groups: salt tolerant and salt sensitive, similar to the result, screened by the traditional methods. Based on these results, a discrimination model was built for identification of salt tolerant cultivars. And then, six other cultivars were used to verify the function of the discriminating model. Result showed that the distinguishing rate of 100% was achieved with the performance index of 85.7%. It is concluded that Fourier transform near infrared spectrum is useful for classification and discrimination of salt tolerance of alfalfa cultivars. The method can be applied to estimate salt tolerance of alfalfa cultivars, and works more quickly and efficiently than the traditional screening methods. Application of Fourier transform near infrared spectrum to discriminating salt tolerance of alfalfa cultivars is significant in both academic and technical areas.

Isolation and characterization of a cDNA encoding a papain-like cysteine protease from alfalfa.

Protein hydrolyzation is activated and involved in response to various stress signals. In the present study, a full-length cDNA, named MsCP1, encoding a papain-like cysteine protease was obtained by degenerated primers and 3'- and 5'-RACE from salt-tolerant alfalfa. The cDNA contained an open reading frame encoding a deduced protein of 350 amino acids with a putative N-terminal signal peptide, NPIR vacuole-sorting signal sequence and potential N-linked glycosylation sites. The deduced sequence showed a high similarity to deduced proteins from pea, tobacco, tomato and ryegrass. Fusion expression analysis in Escherichia coli showed that the putative eukaryotic signal peptide prevented its expression in prokaryotic system. The integration and transcript of the expression elements in transgenic tobacco plants were detected with Southern blot and RT-PCR analysis.